We hypothesize that anesthetics relax the membrane structure, expose the hydrophobic parts of the membrane to the water/membrane interface and decrease the density of the hydrophilic surface charges. Water molecules near the ionic charge decrease the volume about 15% by forming a dense crystalline structure with distorted hydrogen bonds due to the strong electrostatic field imposed upon the water dipole, a phenomenon known as electrostriction. Anesthesia occurs by a transition of a cluster of water molecules changing cooperatively between electrostricted compact state and expanded anesthetized state. The dissolution of the electrostricted water molecules increases the volume of the system and is accounted for the well-established pressure reversal of anesthesia. This study is aimed at a critical evaluation of our hypothesis using phospholipid bilayer and monolayer as model membranes. The thermodynamics of the interaction of anesthetic molecules and phospholipid moleucles are studied by applying high pressure as an antagonist for the anesthetics. Surface tension, surface viscosity and surface potential are measured with monolayers of synthetic phospholipids and the effects of anesthetics are investigated. The ultimate objective is to elucidate the role of water molecules upon the structure and function of the lipid part of cell membranes.